High performance barriers to molecular oxygen (O2) and water are beneficial for some products or processes. For instance, organic and thin film photovoltaics (PV) and organic light emitting devices (OLED) require encapsulation by barriers that are highly resistant to transmission of O2 and water. For PV and OLED applications, barriers must also permit transmittance of relatively high proportions of visible light, in addition to exhibiting relatively high resistance to O2 and water transmission.
Heterostructures comprising layers of metal oxides deposited on substrates show promise as high performance O2 and water barriers. However, the metal oxide layers are typically deposited on the substrates by known low pressure deposition processes such as atomic layer deposition, chemical vapor deposition, and physical vapor deposition.
The known low pressure deposition processes typically require pressure below 1 millibar (mb) and usually below 1×10−3 mb, and also usually require relatively high temperatures that are incompatible with some polymers. The known low pressure deposition processes thus tend to be relatively expensive, slow, and incompatible with some organic polymers, which limits the utility of the low pressure deposition processes for some applications.
The foregoing examples of related art and limitations related therewith are intended to be illustrative and not exclusive. Other limitations will become apparent to those of skill in the art upon a reading or study of related art disclosure.